International Congress on Archives 2004 pres 180 METCALFE C USA GSU 01 E Page 6
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International Congress on Archives
The Genealogical Society of Utah
www.wien2004.ica.org
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standard or widely accepted can mean expensive conversion costs later on if the file format is discontinued or no
longer supported. Proprietary file formats that could be discontinued or under-supported can be a concern.
Those popular file formats in the public domain generally tend to be more stable and allow for longer digital
image conversion cycles.
Digital files can be stored in several different ways. Popular optical media such as CD's and DVDs can be used
to store the digital images. These media types can have life expectancies from as little as 1 year to 100 years
depending on the quality of the original disk. CDs and DVDs containing gold tend to have the longest life.
Magnetic disc storage that is not refreshed can have a life expectancy of 10 years. Magnetic tape has a life
expectancy of 5 15 years. With most of these media, the technology used towrite the digital image on the
media will be outdated before the media fails. A regular program of media testing and refreshing the data should
be undertaken.
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Digital Recapture
On occasion microfilm conversion to digital imaging may not be practical. When microfilm is of poor quality,
the scanned image cannot improve the quality. The best that be hoped for is an accurately scanned poor quality
image. In such cases where the original documents are still available digital recapture of the documents should
be considered. This method can offer several advantages in addition to those listed for microfilm / digital
conversion:
Better tonal ranges can be obtained from the original record when the document is scanned to grayscale or color
digital images. Microfilm tends to increase contrast and distort the actual tonal representation of gray areas of
the document. Digital images of ink-smeared or soiled areas may exhibit text visible to the naked eye but
obliterated on the microfilm copy of the image. Grayscale or color digital images would show more detail in
these low contrast areas.
At the time of digital imaging the image resolution, masking, exposure, and other camera settings can be set to
best suit the particular documents being imaged. This allows the operator to manipulate the camera setting to
achieve the ideal settings to render the documents most favorably.
There is at least one major factor that must be considered when evaluating digital imaging of original records
instead of scanning existing microfilm. Many original records are very fragile. These records may not be able to
withstand the rigors of the physical handling necessary to digitally image them. In some cases the microfilm
images may actually be in better condition than the original documents. In other circumstances, the original
documents may not be available to digitize. In such circumstances, microfilm conversion would be the wisest or
perhaps only choice.
Digital imaging equipment comes in several styles and price ranges. From flatbed scanners to planetary digital
cameras, the imaging equipment can cost USD $100.00 to in excess of USD $75,000.00. Most digital camera
equipment will generally require a computer to operate software that controls the digital imaging device.
Computers must be of sufficient power to handle large graphics files and quickly process images as they are
scanned. As with microfilm scanning, attention must be given to computer disk storage space for the files
created in the scanning process.
Service bureaus can also be found worldwide to image documents in digital formats. Digital imaging on-site or
off-site can be arranged. The prices of digital imaging services range widely based on the number of documents
to be imaged and difficulty in imaging those records.
File format and image size considerations are identical for both microfilm digital conversion and original digital
imaging. Again, a study of the documents will help determine a balance between quality images with larger file
sizes and cost savings and speed of delivery associated with smaller file sizes.
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Metadata
